This section provides background information related to the present disclosure which is not necessarily prior art.
Dental prophylaxis angles, generally referred to as “prophy angles”, are commonly used dental instruments providing rotation for dental tools such as brushes, prophy cups, or other receptacles used in polishing teeth. A prophy angle typically includes a housing having a neck and a head portion extending at approximately a 90° angle to the neck, which increases the ability of a dentist to access the varying teeth surfaces of a patient. A drive shaft may be located within the housing and attached to a driven gear in the head of the prophy angle.
Prophy angles are generally affixed to a handpiece, for powering and driving the prophy angle drive shaft. The handpiece may be powered by any number of sources, such as pneumatic, electrical, or batteries. Prophy angles are commonly manufactured from lightweight plastic to make them inexpensive enough to be disposable, thereby increasing overall sterility in the dental environment. An issue associated with making the prophy angles, and their constituent elements, such as the driven gear and drive shaft, from plastic is the ability of the handpiece to engage the drive shaft and the driven gear without excessive damage to the prophy angle.
A reduction in the number of component parts needed for constructing and assembling a prophy angle is desirable. In addition, designing the component parts to cooperatively operate with other component parts reliably and in an efficient manner is also desirable.
A standard well known doriot-style prophy angle includes a generally cylindrical or frustoconical inner wall that mates with a similarly-shaped nosecone of a handpiece. In addition, the doriot-style prophy angle typically includes a notched section that fits with a mating protrusion on the handpiece to key or orient the prophy angle with respect to the handpiece. For a handpiece having an angle-adjustable nosecone, the notched section and frictional forces may provide an unsatisfactory fixation force, between the prophy angle and the nosecone, not allowing the desired angle of the nosecone to be reliably locked and unlocked, during a procedure, because the prophy angle may slip/rotate with respect to the nosecone. Therefore, for a handpiece nosecone having an adjustable angle, providing an easy, quick, and reliable way of adjusting the angle and setting or locking the desired angle is desirable.